Patent GB-189924040-A (GB)
Title: Improvements in Type-writing Machines.
Inventor: GREEN JOHN JAY
Filed: 1899-12-02
Granted: 1900-05-12
Abstract: 24,040. Green, J. J. Dec. 2. Type - writers. - Relates to type-writers of the index-wheel class. Fig. 1 shows the machine in plan, and Fig. 5 in transverse section. The carriage is mounted upon a frame 6 pivoted at 7 to the main frame of the machine. A spring 27 acting upon the front of the frame 6 normally maintains the platen 26 in its uppermost position, for printing lower-case type. The frame 6 is, however, linked to a lever which is partly depressed when the shift key 127 is actuated, or is fully depressed by the actuation of the key 128. The frame 6 and platen 26 can thus be caused to occupy either of three positions according to the nature of the character to be printed. The carriage is guided by a central rail 13 on the frame 6, and by a pillar 25 having a slot 24 in which the rear bar 23 of the carriage rests. The front bar 18 of the carriage carries the ratchet - bar which constitutes a part of the letterspacing device. The type-wheel 34 is provided with three rows of characters, and is mounted on a sleeve 33 free to turn on a rod 32, which is rigidly secured to a carrier frame 30 pivoted to the main frame at 29. A pillar 38 on the frame 30 supports an arm 39 which carries a thimble into which the upper end of the rod 32 fits, perfect rigidity being thus secured. A notched lug 40 serves as a sight for locating the impression point. In rigid connection with the type-wheel is a wheel 44 having a groove for the accommodation of a cord or chain 46, Fig. 1, which terminates in a leather loop 73. To the under face of the wheel 44 is secured a ring having ten large teeth 47, the bevelled edges of which co-operate with one or other of three pivoted dogs 69 for the purpose of accurately positioning the type at the moment of impression. A coiled spring 48 tends to bring the type-wheel back to its normal position. The keyboard consists of three bars 49, each bearing ten character-buttons 50. The bars, when depressed, operate the levers 56, 57, or 58, which actuate the three dogs 69. In operation, the loop 73 is slipped round the index finger of the operator, and the keys are then depressed in turn. The movement of the cord 46 brings the type-wheel into an approximately correct position, and the proper character is brought accurately to the impression-point by the action of one of the three dogs 69. The dog rises as the bar 49 is depressed, and after positioning the type-wheel the dog rocks the whole frame 30 on its pivots and brings the type into contact with the platen. The pulley 71 round which the cord 46 passes is mounted on a spring-controlled arm 72 capable of yielding under any excessive tension of the cord. The inking-ribbon 85 is wound on spools 91, and is guided through slots in plates 94 at opposite ends of the carriage. It is adjusted by occasionally turning one or other of the knobs 92, and receives a supply of ink from rollers 97 on the main frame. The paper is conducted to the platen by means of a sheet-metal guide 100 terminating in a feed-roller 102. The feed-roller is spring-pressed against the platen, but can be released by a suitable lever. A V-shaped wire loop 104 partly embraces the platen, and the types strike through it. Line-spacing is effected by turning the knob 105, equal spacing being ensured by the use of a spur-wheel 106 with which engages the V-shaped end of a spring 108 which acts as a detent. The spring 108 can be released by a lever 111 when it is desired to turn the platen freely. The carriage is tensioned by a cord passing round the spring drum 135, the feed being controlled by an escapement device consisting of fixed and movable dogs 143, 147, shown more clearly in Fig. 11. The escapement device is pivoted to a lug depending from a bar 139, which is rocked by the action of either of the key-bars 49 on the universal bar 151, or by the depression of the spacing-key 154. The dogs 143, 147 can be lifted out of engagement with the carriage rack by means of a pivoted rod extending along the front of the carriage, which can then be moved freely. When the carriage has advanced within a short distance of its extreme left-hand limit, a toothed plate carried by it actuates levers which lock the rocking-bar 139, and thus prevent depression of the keys, but by means of a key 169 the levers can be released so as to allow a few more letters to be printed. The margin is regulated by adjustment of a ratchet-bar 174 having a shoulder 178 against which the projection 110 on the carriage abuts when commencing a new line.